Mortgage calculators are programmed with the ad hoc purpose of calculating monthly payments to be done on a mortgage. Such calculators are called mortgage payment calculators. These calculators can also do amortization schedules.

Mortgage payment calculators are different from simple mortgage calculators. They not only compute the interest payable per month, they also split the principal according to the tenure of the mortgage. The payment is usually a sum of the portion of the principal to be paid in that month, along with the interest payable.

Several mortgage payment calculators are freely available online. They need the amount of mortgage taken, current rate of interest and the tenure of the mortgage as inputs. There is a calculate tab which, when clicked, will calculate and display the monthly payments. A further click on an amortize tab would display a detailed chart showing the entire schedule of payments. Some mortgage payment calculators have separate tabs asking for annual taxes payable to the state on their property plus insurance, if any. Such calculators need the zip code. These are added to the monthly payment. If a down payment is done, then that amount is deducted from the calculation. Some mortgage companies require fixed monthly down payments. Mortgage payment calculators deduct all such down payments and display a final figure.

Mortgage payment calculators are an essential feature of mortgage-selling websites. They are very simply programmed so that even a layman can use them. In fact, people nowadays use these free online mortgage calculators even before approaching financial institutions for a mortgage. This gives them a picture of how much they can afford and how much they will have to pay per month. Some websites provide three mortgage calculators alongside each other, so that users can fill in three different scenarios and check out what is best suited to them.